Conservation Laws

There are many forms of energy - mechanical, chemical, electrostatic, heat, nuclear. In any isolated system, energy can be transformed from one kind to another, but the total amount of energy is constant (conserved). Example: a battery contains chemical energy and can be used to produce mechanical energy. Example: when a block slides over a rough surface, the force of friction gives rise to the heating of block and surface. As a result, mechanical energy is transformed into heat energy, but total energy is constant. In this chapter, we are interested in two kinds of mechanical energy:

• Kinetic Energy ( KE ) (energy of motion)
• Potential Energy ( PE ) (energy of position)